Function pointer for templated class method

Question

Hi everyone, I need a hand to solve this problem, I'm trying to create a function that allows me to call a class method passed as a parameter of the aforementioned function, only that once I compile the code I get this error:

src\main.cpp: In function 'void setup()':
src\main.cpp:38:37: error: invalid use of non-static member function 'void esp8266webserver::ESP8266WebServerTemplate<ServerType>::handleClient() [with ServerType = WiFiServer]'
38 | b25.handler.when_connected(server.handleClient);
| ~~~~~~~^~~~~~~~~~~~
In file included from ..\..\..\..\.platformio\packages\framework-arduinoespressif8266\libraries\ESP8266WebServer\src/ESP8266WebServer.h:340,
from src\main.cpp:4:
..\..\..\..\.platformio\packages\framework-arduinoespressif8266\libraries\ESP8266WebServer\src/ESP8266WebServer-impl.h:274:6: note: declared here
274 | void ESP8266WebServerTemplate<ServerType>::handleClient() {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Answer 1

I'm working with esp8266 board in PlatformIO in VSCode.

The line
b25.handler.when_connected(callbackfunction_t callback);

where

typedef void(*callbackfunction_t)(void);

Answer 2

These lines together generate the error described above.

Answer 3

Mick ,

I don't know much about C++, but it'd be helpful if you link us to your code, like this:
https://sololearn.com/compiler-playground/c9XEgLk7ipsR/?ref=app
And, you can send us a screenshot of your error by sending us a link to your screenshot, which can be done using this website: https://imgur.com/

Answer 4

I hope you'll receive useful answers! I'm sorry I can't help you since I'm not a C++ developer.

Answer 5

code?

Answer 6

The method I am trying to pass as a parameter to this function is on line 109 of this library

handleClient();

link: https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266WebServer/src/ESP8266WebServer.h

Answer 7

// orvibo_handler.h:
typedef void(*callbackfunction_t)(void);

// orvibo_handler.cpp:
void OrviboHandler::when_connected(callbackfunction_t callback) {
/* type: callbackfunction_t */ when_connected_function_pointer = callback;
}

Answer 8

Code that generate the error:

//main.cpp:

b25.handler.when_connected(server.handleClient);

Answer 9

have you tried compiling the test example first to see if your setup runs ok?